Have you ever been around a cat that, suddenly and seemingly without warning, attacked you or someone else in the home?

When this happens, it can seem like your cat is suddenly possessed by a tiger. But she may have a reason for this behavior: redirected aggression.

What Is Feline Redirected Aggression?

Redirected aggression happens when a cat sees or senses what she considers to be a threat or is hyper-stimulated by something but is unable to respond to it directly.

Causes of Redirected Aggression in Cats

Redirected aggression occurs when a cat is scared, overstimulated, or angry about something and is unable to deal with the problem directly. Here are some common scenarios that trigger redirected aggression in cats:

An indoor cat sees or senses an intruder cat in the yard through a window. The cat in the home becomes agitated, wishing to defend her territory from the visiting cat but not being able to get to him. Unable to deal with the intruder directly, the cat instead attacks who or whatever is closest, usually an owner or feline or canine housemate.

Something badly startles the cat, but she isn't aware of the cause of the frightening stimulus. This could be a loud, scary sound on the TV, something falling and crashing near the cat, or anything else that is sudden and alarming.

Prey such as squirrels or birds are seen through a window, but the indoor cat is unable to chase them.

Redirected aggression happens commonly in homes with multiple cats and one or more dogs. A cat might become frightened by the dog but not be brave enough to attack him, so she goes after one of her feline housemates instead.

Pain can cause redirected aggression. Cats sometimes associate pain they are feeling with an animal or person near them.

If you or another person in your home is bitten or scratched by your cat, consult with your doctor right away. Cat bites, especially, can quickly become serious if they aren't properly treated.

Redirected Aggression in Cats Can Snowball

If one cat in your home attacks another cat out of redirected aggression, the next time the aggressor sees the victim, the same fear or territorialism may be triggered, causing another attack. So aggression that was originally triggered by an outside source can develop into one cat that continuously terrorizes another.

Diagnosing Feline Redirected Aggression

It can be difficult to determine whether the original cause of a cat's aggressiveness was due to redirection. Unless an owner sees and correctly interprets an inciting incident, it may be tough to establish the diagnosis.

In fact, a redirected attack can occur minutes or hours after the inciting event. The kitty becomes progressively more agitated thinking about, for example, the intruder cat hanging around outside and suddenly "snaps," attacking a housemate.

One clue that redirected aggression may be the culprit is that cats that previously got along well for long periods seem to suddenly be experiencing a burst of aggression and in-fighting.

What to Do About Feline Redirected Aggression

If your cat is acting aggressively toward another cat in your home, separate them. Many people will attempt to allow them to "work it out," but this usually just leads to an escalation of the aggression and increased terrorization of the "victim" kitty, which may result in injuries or the development of inappropriate behaviors such as urinating outside of the litter box. Separating the cats until they are exhibiting calm behavior and then reintroducing them to one another slowly, in supervised conditions only, can de-escalate the situation and break the snowball pattern described above.

If your cat is showing sudden aggression, have her checked out by her veterinarian, since pain and illness can lead to redirected aggression.

Use Feliway to help calm the aggressor. You can use the spray at nose level around the room in which your kitty seems to become aggressive, or you can use a diffuser.

Never get in the middle of a cat fight. Not only could you be injured, but the aggressive cat may further redirect her efforts toward you. Instead, try shaking a can full of pennies or squirting water in the direction of the fighting cats (try not to let them see you when you do this).

Disclaimer: This website is not intended to replace professional consultation, diagnosis, or treatment by a licensed veterinarian. If you require any veterinary related advice, contact your veterinarian promptly. Information at CatHealth.com is exclusively of a general reference nature. Do not disregard veterinary advice or delay treatment as a result of accessing information at this site.